In a statement, the EPA said its study found some mercury and other metals, but that they were well under the state Health Department threshold for discharge into the nearby Valatie Kill.

The EPA said it will allow the two 20,000 gallon tanks that were tested containing treated groundwater to be discharged into the waterway on Friday.

Residents and local elected officials have pressed for a comprehensive health study and cleanup of the site.

A 16-acre property, Dewey Loeffel landfill contains 46,000 pounds of PCBs, solvents and other toxic chemicals from General Electric Co., the former Schenectady International (now SI group) and Bendix Corp. The chemicals were dumped there from 1952 until a court order closed the site in 1970.

A water treatment plant at the site was built to treat contaminated groundwater so it doesn't need to be moved to another plant. The EPA said it has been working to make sure water is treated properly before it is released into Valatie Kill.

Last year, the Health Department and the federal Agency for Toxic Substances and Disease Registry concluded that a health study of residents was not needed, partly because a 2002 state review found that 10 years of cancer rates around the dump were not higher than the rest of the state's.

Residents and elected officials have been pushing strongly for health studies. Rensselaer County Legislator Alex Shannon last month said residents around the landfill have lived "under a toxic shadow for over 50 years.